Do we have everything we will ever get once we are saved and born again?
No. Salvation and the new birth give a great deal—the soul and spirit are redeemed—but believers still do not have it all. They groan within themselves, waiting for the adoption, the redemption of the body, which will complete everything.
Les explains that the child of God has received much through salvation and the new birth: the soul and spirit are redeemed. Yet the context says, 'We haven't got it all yet.' Believers still groan within themselves, waiting for something more. That remaining piece is the adoption, that is, the redemption of the body. When that takes place, it will complete it. Creation also groans under the curse, waiting to be delivered into the glorious liberty of the children of God, and believers are joint heirs with Christ.
And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body.